docs: def _get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types, 
          mag_conversion_sigma=0.0):
          """
          See :meth:`superclass method
          <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
          for spec of input and result values.
          """
          # extract dictionaries of coefficients specific to required
          # intensity measure type
          C = self.COEFFS[imt]
  
          # clip distance at 4 km, minimum distance for which the equation is
          # valid (see section 2.2.4, page 201). This also avoids singularity
          # in the equation
          rhypo = dists.rhypo
          rhypo[rhypo < 4.] = 4.
  
          mean = C['a'] * rup.mag + C['b'] * rhypo - np.log10(rhypo)
  
          mean[sites.vs30 >= 800] += C['c1']
          mean[sites.vs30 < 800] += C['c2']
  
          # convert from log10 to ln, and from cm/s2 to g
          mean = mean * np.log(10) - 2 * np.log(10) - np.log(g)
  
          stddevs = self._get_stddevs(C, stddev_types, rhypo.shape[0], 
              mag_conversion_sigma=mag_conversion_sigma)
  
          return mean, stddevs